Weeds of national significance
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1.9Program Logic Model for African boxthorn (Lycium ferocissimum)Vision: The extent and potential of African boxthorn in Australia will be well understood, stakeholders well equipped with information tools and knowledge, and strategic management will contain and reduce the weed’s impacts. 
Technical Background1.10African boxthorn identificationAfrican boxthorn (Lycium ferocissimum) is a densely branched, perennial shrub growing to 4m high, but more often 2-3m. Branches end in sturdy thorns. It has slightly fleshy, oblong leaves up to 40mm long, growing in clusters. Flowers are approximately 10-12mm in diameter and hang from the leaf axils on stalks, singly or in pairs. They are white to lilac, have five petal lobes, often with a lilac base to each lobe. Fruit is 5-12 mm long starting with a smooth green appearance and ripening to an orange-red berry. There are numerous native flora species that could be mistaken for African boxthorn. For example, Australian boxthorn (Lycium australe) grows across southern mainland Australia, mainly in drier areas west of the Great Dividing Range. Other examples of Australian natives with similar appearance include tree violet (Hymenanthera dentate), native gorse (Daviesia ulicifolia), and spiky anchor plant (Discaria pubescens). 1.11African boxthorn biology and ecologyAfrican boxthorn is a native of South Africa and has become widely established in Australia having being deliberately introduced as a hedge plant during the nineteenth century. The species mostly flowers and seeds in summer, but can do so year round. Seedlings germinate at any time of the year. Flowering and seeding begins when plants are two years of age. Boxthorn has a long, deep root system and soil disturbance results in the root system sending up shoots. 1.12African boxthorn distribution and spreadFrom the mid 1800s African boxthorn appeared in Australian nursery catalogues, was grown in botanical gardens, and was recommended for planting as a hedge plant. African boxthorn has been recorded in all states and territories in Australia and is one of the nation’s most widespread weeds. A map of African boxthorn distribution in Australia is included in the appendices (section 7.2). It thrives in island and coastal through to semi-arid environments, and from temperate to sub-tropical climate areas. Dispersal is primarily via seed with the fruits being consumed by animals including birds and foxes. When seeds are excreted, they remain viable. Distribution by birds makes even localised eradication and containment of the species challenging to achieve. African boxthorn is found on island and in coastal situations in most states of Australia, and readily displaces local native vegetation. Being spread by birds it is found on relatively remote island and coastal areas (such as in Bass Strait for example). It is widespread through inland areas being, for example, an important weed across all of inland NSW. Spread via birds means that boxthorn often occurs under trees, poles and fences. However, it is generally found where annual average rainfall exceeds 200mm. In semi-arid environments infestations occur along dry stream beds. 1.13Summary of impactsAfrican boxthorn invades native vegetation, pasture and other areas (such as unused and mining lands). Once in place, it provides habitat for pest animals like rabbits and foxes, and in areas with quality native vegetation, it reduces habitat available to native fauna. The large thorns on boxthorn can be hazardous to native fauna such as shorebirds. Boxthorn can create impenetrable thickets that exclude desirable vegetation (native vegetation and pasture), and impede stock movement. Parts of the boxthorn plant (fruit and leaves) are thought to be slightly poisonous to people and livestock. African boxthorn plants have large thorns and these can – even long after the plant is dead – cause injury to people, livestock and wildlife, and even pierce tyres. 1.14Control optionsIn certain situations (such as where native vegetation is in a poor state or isn’t present) African boxthorn can provide habitat for native fauna. This should be taken into consideration in planning for control works. In some situations, such as with the orange-bellied parrot in Victoria and South Australia, and Australian sea lion in Western Australia, boxthorn is providing essential habitat for threatened species. Effective control of African boxthorn requires the integration of a number of methods. Any one control method applied alone will not provide for long-term control. Control needs to be planned and to incorporate monitoring and follow-up. Following up on the seed bank and any reshoot from root stock is critical to long term control success. 1.14.1Chemical and physical controlChemical control of African boxthorn can be undertaken through foliar, basal bark, cut stump, or (where suitable) soil application techniques. Boxthorn grows as a dense and thorny shrub and so basal bark and cut stump techniques can be physically difficult or impossible to apply. Where boxthorn is growing in significant infestations, physical removal and burning is the most cost effective option. Follow up treatment with herbicide and/or cultivation are essential as boxthorn readily regrow’s from root stock and seed. Monitoring of the treatment site for at least several years is also essential. Revegetation with native species is recommended to help discourage re-establishment of African boxthorn, and provide habitat for native fauna. 1.14.2Biological controlNo biological control agents are currently available for African boxthorn in Australia. CSIRO are aware of at least one potential agent, a rust fungus, which is found on African boxthorn in South Africa. Promoting investigation of the potential for introduction and use of biological control agents is included as an action (3.4.2) in this strategy. 1.15Quarantine and legislation
Appendices1.16Weed control contacts
1.17Current distribution of African boxthorn (Lycium ferocissimum) in Australia 
1.18Other information sourcesAfrican boxthorn is as of 2012, a Weed of National Significance. Information and resources, as they become available, will be posted at www.weeds.org.au/WoNS/africanboxthorn/. 1.19DefinitionsAsset protection – A weed management approach to reduce impact or threat on an asset Containment - A weed management approach that aims to prevent an increase in the current distribution of a weed, by using weed control procedures to reduce the density of existing infestations and limit the dispersal of propagules. Highly effective containment programs can actually result in a decrease in the current distribution of a weed. Coordinated control - A strategic weed management program that takes into consideration all occurrences of a weed, and involves the application of weed control procedures towards a specific end (e.g., eradication or containment). Core infestation – weed infestation which is large and non eradicable for a defined scale Eradication -The elimination of every single individual of a species from an area to which recolonisation is unlikely to occur, including propagules (Myers et al. 1998). Outliers – infestation separate from core and may be eradicable Priority outliers – feasible to eradicate or contain or reduce / prevent spread Priority assets –high value (environmental, primary production, cultural and social) assets determined to be at risk – can be applied at varying scales, and includes defined national and jurisdictional values Partner – Person(s) or organisation actively supporting weed management Stakeholder – person, group or organisation interested in or concerned about weeds and or their management 1.20GlossaryACT – Australian Capital Territory AQIS – Australian Quarantine Inspection Service AWC – Australian Weeds Committee AWS – Australian Weed Strategy BPWW – Biodiversity Priorities for Widespread Weeds CMA – Catchment Management Authority CSIRO – Commonwealth Scientific and Industrial Research Organisation MERI – Monitoring, Evaluation, Reporting and Improvement NRM – Natural Resource Management WoNS – Weeds of National Significance 1.21ReferencesMagnussen, C. 2011 Weed Management Guide – African Boxthorn (Lycium ferocissimum). Queensland Government, Brisbane.Muyt, A. 2001. Bush Invaders of South-East Australia. R.G. and F.J. Richardson, Victoria.Myers, J.H., Savoie, A., and van Randen, E. 1998. Eradication and pest management. Annual Review of Entomology. Vol. 43, pp. 471-91. Parsons, W.T. and Cuthbertson, E.G. 2001. Noxious Weeds of Australia. CSIRO Publishing, Victoria. Richardson, F.J., Richardson, R.G. and Shepherd, R.C.H. 2007. Weeds of the South-East – an identification guide for Australia. R.G. and F.J. Richardson, Victoria.Wilson, P.D., Downey, P.O., Gallagher, R.V., O‘Donnell, J., Leishman, M.R. and Hughes, L. (2011) Modelling climate suitability for exotic plants in Australia under future climate. Final Report on the potential impact of climate change on the distribution of national priority weeds in Australia. Macquarie University and New South Wales Office of Environment and Heritage, Sydney, Australia. Ziegler, K. And Hopkins, K. 2011. Furneaux Islands - Boxthorn Control. Friends of Bass Strait Islands – Wildcare. Tasmania. |